Polyester From Furfural
Polyester is a synthetic polymer made of purified terephthalic acid (PTA). Furan-2,5-dicarboxylic acid (FDCA) has been suggested as an important renewable building block because it can substitute for terephthalic acid (PTA) in the production of polyesters . The synthesis of furfural to FDCA is a two step reaction, via furoic acid . It is very old chemistry that goes back to 1930s. Most recently commercial developments of FDCA is based on 5-Hydroxymethylfurfural (5-HMF) as precursor.
By 2020, the FDCA Market volume is expected to reach about 500,000 tpa. 
Why FDCA from Furfural?
The current (semi-)commercial production of FDCA is made via 5-HMF, which is an unstable molecule and requires expensive catalysts for its synthesis. In addition, its commercial viability depends on large-scale production and is reliant on the food industry to supply sugars and/or starches.
Furfural is made on small-scale production units (biorefineries) that are close to the biomass suppliers or attached to a sugar mill (or pulp mill).
Furfural production does not interfere with food-production.
Furfural production contributes to food-security, as its beneficiaries are the farmers, whose crop "wastes" are used to generate additional revenue for them.
Furfural biorefineries have a high socio-economic impact: They require low capital investments and are suitable to be owned and operated by small enterprises or co-operatives and therefore have a direct impact on their local economies (inc. creation of green, rural jobs).
Editor's note: The Furfural-to-FDCA research goes back to the early 20th century. Since the 1970s, new catalysts, new process technology, etc. have been developed in the hydrocarbon-based chemical industry, which could also be applied in the bio-renewable chemicals space. The background IP for Furfural-to-FDCA is freely available and given the low-cost/energy efficient furfural production that is commercially available from International Furan Technology, there should be no reason to meet the targeted US$1,000 per tonne of FDCA.
Furfural as feedstock for PET alternatives (December 2013)
Renewable platform chemical and building block (October 2013)
Bioplastics: 500% growth = 500% more green chemicals (September 2013)
 B. Kamm, M. Kamm. M. Schmidt, T. Hirth and M. Schulze, Biorefineries – Industrial Processes and Products, ed. B. Kamm, P.R. Gruber and M. Kamm, Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim, Germany, 2006, vol. 2, ch. 3, pp. 97-149.